Davao, 12 September 2009. Ask any elementary pupil if he knows what the country’s national tree is and he will reply, “Narra.” But ask him how narra looks like and he will not utter a word. The reason: most children these days don’t see any narra tree.
In fact, narra is on the brink of extinction and only the most determined and relentless conservation campaign will preserve it. “Today, the Philippines has only small, scattered and endangered remainders of the tree,” laments Roy C. Alimoane, director of Mindanao Baptist Rural Life Center (MBRLC) Foundation Inc. based in Kinuskusan, Bansalan, Davao del Sur.
The MBRLC is campaigning for its mass production with its reforestation projects. “This nitrogen-fixing tree can grow to a height of 33 meters and a diameter of 2 meters,” Alimoane says.
In other parts of Asia where the tree grows, narra is facing the same threat. While it is recorded as “vulnerable” in the Philippines, narra is “threatened” in Indonesia and “endangered” in India. It is probably now extinct in Peninsular Malaysia because of exploitation – of its few known stands. Narra has been extinct for 300 years in the wild of Vietnam.
In 1987, the Philippine government prohibited the felling down of narra trees and its collection in natural stands. However, the forest-cultivation for industrial purposes was excluded from this regulation. Today, the remainders of narra trees can only be found at the coast of Isabela, in Bicol, in Mindanao and in the forests of Cagayan.
In Singapore, narra is a symbol of the country’s garden city planting program. This attractive tree graced many Singaporean avenues. In Chonburi and Phuket in Thailand, narra is the provincial tree. In Malaysia, narra has been planted as a shade tree for at least 200 years.
Leguminosae
Narra is adapted to flat, coastal plains behind mangrove swamps, sites along streams in the low hills near the coasts or inland valleys, and primary and secondary forests. It is generally found growing in calcareous soils or soils not deficient in calcium. It prefers mist sandy loam or clay loam soils.
Narra belongs to the plant family called Leguminosae which has about 20 species in the world but only four can be found in the Philippines. Except for botanists and foresters, the species are difficult to distinguish from each other.
Narra is called a variety of names in the country: naga, nalu, antagan, apalit, asana, bitali, dungon, lagcr, hagad, sagat, tagga, tagka, agana, balauning, bital, daitanag, kamarag, udiao, and vitali. The four Philippine species of narra are:
- Narra (Pterocarpus indicus). This is the tree that produces the wood under which the other species usually come and are marketed. It grows in almost all parts of the country. The seed pods are smooth and with spines or hairs;
- Prickly narra (P. vidalianus). This is found in many parts of Luzon, Mindoro, Leyte, and Palawan. It is fairly abundant in Cagayan and Northern Luzon. Its seeds have short, soft spines, hence the name;
- Hairy-leaf narra (P. pubesceus). Found only in the Mountain Province, it is almost similar to the other species in features, except for its soft hairy covering on the leaves; and
- Blanco narra (P. blancoi). This is found in La Union, Nueva Ecija, Bulacan, and Rizal. It is distinguished from the others by its fruits, which are larger than those of P. indicus.
Like many trees, narra has three limitations: It has tendency to fork; it is susceptible to fire injury (this is due to its thick bark but it recuperates well); and its branches may break in strong winds.
T.E. Hensleigh and B.K. Holaway, editors of Agroforestry Species for the Philippines, say that narra seeds are widely available during the months of January in Nueva Ecija, Leyte, and Zamboanga; February in La Union; March in Ilocos; April in Masbate, Benguet, Quezon, and Surigao; May in Ticao; June in Bulacan, Agusan, and Sorsogon; July in Tarlac and Cagayan; July and August in Laguna; September in Rizal, Capiz, and Mindoro; and October in Tablas, Negros.
The narra seeds can be picked up from the ground underneath the trees and stored in open containers for a year or more. One kilogram of narra fruits has about 1,200 to 1,300 seeds or 140 seeds per liter.
Narra flowers and fruits
Narra is very attractive because of its flowers. “The flowers are yellow, fragrant, and borne in large axillary panicles. When flowering, the buds do not open in daily sequence. Instead, as the buds come to full size, they are kept waiting to be triggered into opening. The opened flowers last for one day. After that, several days may pass before another batch of buds opens,” the Hawaii-based Nitrogen-fixing Tree Association said.
The nature of the trigger is unknown. It is widely planted along the roadsides, and parks. In the Philippines, narra trees bear profuse bright yellow and fragrant flowers from March to April.
The narra fruit is disc-shaped and has a winged margin. Each fruit, which has one to three seeds, takes four months to mature. But unlike most legumes, of which narra is one, the narra fruit is indehiscent and dispersed by wind. It also floats in water and can be water dispersed.
Narra as timber
Narra is highly esteemed because of its timber. “It (timber) is moderately hard and heavy, easy to work, pleasantly rose-scented, takes a fine polish, develops a range of rich colors from yellow to red, and has conspicuous growth rings, which impart a fine figure to the wood.”
Regarding the strength properties of narra, the Woodworkers Source said that the bending strength of air-dried wood of narra is similar to that of teak, which is considered to be strong. Strength in compression parallel to grain is in the high range. Other species in this range include teak, white oak and hard maple. It is moderately hard and resistant to wearing and marring. It is a heavy wood. The wood is high in density.”
As furniture, one author commented: “In durability, in beauty of its grain, and in the beautiful finish it takes, narra ranks with the best cabinet woods in the world.” It is used in the manufacture of high-quality furniture, peels and veneers, paneling, and parquet-floors. The narra wood, if it is available, is also preferred for the manufacture of inlays, musical instruments, clocks, piece-works, billiard tables, piano cases, and sculptures.
Narra's medicinal values
In the past, narra is used to combat tumors. This property might be due to an acidic polypeptide found in its leaves that inhibited growth of cancer cells by disruption of cell and nuclear membranes. During the 16th and 18th centuries, narra was valued as a diuretic in Europe.
Since the old days, tea prepared from the narra leaves had been a remedy against boils and diarrhea in traditional medicine. In recent years, the extracts of the narra as remedy for some diseases are discovered again by modern medicine.
Unknowingly, the narra flower is used as a honey source while leaf infusions are used as shampoos. Both flowers and leaves were said to be eaten. The leaves are supposedly good for waxing and polishing brass and copper.